Abstract

Spectral features are powerful cues in the perceptual organization of soundsequences. The ‘‘peripheral channeling’’ explanation of stream segregation predicts that the perception of fusion or fission in sequences, in a repeating ABA format, depends on the degree of spectral overlap of the A and B sounds. Nevertheless, previous studies have shown that other factors can also affect auditory stream segregation. Sequences of fully unresolved complex tones,bandpass filtered in the same frequency region, have been shown to perceptually split apart into two streams when the fundamental frequencies of the complexes are widely separated [Grimault etal., J. Acoust. Soc. Am. 108, 263–271 (2000)]. In the present experiment, normally hearing adults heard rapid alternations of a pair of flat‐spectrum, sinusoidally amplitude‐modulated broadband noise bursts. These noise bursts were segregated based on differences in modulation rate, as determined with a constant stimulus procedure as well as with a procedure in which segregation responses were collected continuously while the modulation rate of B was swept up or down during a block of trials. [Work supported by Fondation pour la Recherche medicale and NIDCD.]